C# Challenge ( ADDRESS BOOK )

Question

Hi! I've been studying C# and the principles of OOP, I've been challenged to make a program ADDRESS BOOK and maybe I could ask for your help :D, I want to know if the code I've written is a good practice or bad practice, please guide me :'(

THANK YOU VERY MUCH :) BLESS You :D :D

PROBLEM : Address Book

Write a program that functions as an address book. It should have entries containing at least the following information: first and last name, phone number, address, and email address. At a minimum you’ll want an address book entry class. You should be able to add entries and search for entries (by last name at a minimum).

Program.cs

using System;

namespace Treehouse
{
class Program
{
    public static void Main()
    {
        AddressBookEntry AddressBook = new AddressBookEntry(50);

        Console.WriteLine("Address book options:\n"+
                             "add - to add new entry.\n"+
                             "search - to search entry.\n"+
                             "quit - to leave.\n"+
                             "clear - to clear screen\n"+
                             "options - display instructions\n");
        while(true)
        {
            Console.Write("Option: ");
            string Instruction = Console.ReadLine();

            if(Instruction.ToLower() == "quit")
            {
                Console.Clear();
                Console.WriteLine("GoodBye!");
                break;
            }
            else if(Instruction.ToLower() == "add")
            {
                Console.Clear();
                AddressBook.NewEntry();
            }
            else if(Instruction.ToLower() == "search")
            {
                Console.Clear();
                AddressBook.SearchEntry();
            }
            else if(Instruction.ToLower() == "clear")
            {
                Console.Clear();
            }
            else if(Instruction.ToLower() == "options")
            {
                Console.Clear();
                Console.WriteLine("Address book options:\n"+
                             "add - to add new entry.\n"+
                             "search - to search entry.\n"+
                             "quit - to leave.\n"+
                             "clear - to clear screen\n"+
                             "options - display instructions\n");
            }
            else
            {
                Console.WriteLine("Invalid Input!");
            }
        }
    }
  }
}

Person.cs

using System;

namespace Treehouse
{
class Person
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string PhoneNumber { get; set; }
    public string HomeAddress { get; set; }
    public string EmailAddress { get; set; }

    public string GetInfo()
    {
        string message = "First Name: {0}\nLast Name: {1}\nPhone Number: {2}\nHome Address: {3}\nEmail Address: {4}\n";
        return string.Format(message,FirstName,LastName,PhoneNumber,HomeAddress,EmailAddress);
    }
  }
}

AddressBookEntry.cs

using System;

namespace Treehouse
{
    class AddressBookEntry
    {
    private Person[] _entries;
    private int _totalEntries = 0;

    public int Size { get; private set; }

    public AddressBookEntry(int size)
    {
        _entries = new Person[size];
        Size = size;
    }

    public void NewEntry()
    {
        if(_totalEntries < _entries.Length)
        {
            Console.WriteLine("New Entry:");
            Person person = new Person() {
                FirstName = InputValidator.LetterInput("First Name: ", "Input should only be letters please try again."),
                LastName = InputValidator.LetterInput("Last Name: ", "Input should only be letters please try again."),
                PhoneNumber = InputValidator.NumberInput("Phone Number: ", "Input should only be number please try again."),
                HomeAddress = InputValidator.AnyInput("Home Address: "),
                EmailAddress = InputValidator.AnyInput("Email Address: ")
            };

            _entries[_totalEntries++] = person;

            Console.WriteLine("Added successfuly!");
        }
        else
        {
            Console.WriteLine("Address Book is already full.");
        }
    }

    public void SearchEntry()
    {
        Console.Write("Type the number of the field you want to search\n"+
                          "[1] First Name \n[2] Last Name \n");
        string result = "No result found!";
        string Option;
        while(true)
        {
            Option = InputValidator.NumberInput("Option: ", "Input should only be number please try again.");
            if(Option == "1" || Option == "2")
            {
             break;
            }
            Console.WriteLine("Invalid Input.");
        }

        if(_totalEntries == 0)
        {
            result = "Address Book is Empty.";
        }
        else
        {
            for(int i = 0; i < _totalEntries; i++)
            {
                Person person = _entries[i];

                if(Option == "1")
                {
                    string search = InputValidator.LetterInput("First Name: ", "Input should only be letters please try again.");
                    if(person.FirstName.ToLower() == search.ToLower())
                    {
                        result = person.GetInfo();
                        break;
                    }
                }
                else if(Option == "2")
                {
                    string search = InputValidator.LetterInput("Last Name: ", "Input should only be letters please try again.");
                    if(person.LastName.ToLower() == search.ToLower())
                    {
                        result = person.GetInfo();
                        break;
                    }
                }
            }
        }

        Console.WriteLine(result);
    }
  }
}

InputValidator.cs

using System;
using System.Text.RegularExpressions;

namespace Treehouse
{
static class InputValidator
{
    public static string AnyInput(string label = "Input string: ", 
                              string errorMessage = "Input must only be letters.")
    {
        string input;
        Console.Write(label);
        input = Console.ReadLine();
        return input;
    }

    public static string LetterInput(string label = "Input string: ", 
                              string errorMessage = "Input must only be letters.")
    {
        string input;
        while(true)
        {
            Console.Write(label);
            input = Console.ReadLine();
            if(!(new Regex("[0-9]").IsMatch(input)))
            {
                break;
            }
            Console.WriteLine(errorMessage);
        }
        return input;
    }

    public static string NumberInput(string label = "Input string: ", 
                              string errorMessage = "Input must only be numbers.")
    {
        string input;
        while(true)
        {
            Console.Write(label);
            input = Console.ReadLine();
            if(!(new Regex("[a-zA-Z]").IsMatch(input)))
            {
                break;
            }
            Console.WriteLine(errorMessage);
        }
        return input;
    }
  }
}

Answer 1 · 2017-05-17T11:36:42Z

May 17, 2017 11:36am

This looks great! I only have a few nitpicks, really, that I can tell.

The Person.GetInfo looks like it can be refactored to just override the ToString method.
For the regex in InputValidator, I wonder if you could just use a int.TryParse instead. There's a famous quote about regex from Jamie Zawinski that always comes to mind when I think about it:

Some people, when confronted with a problem, think "I know, I'll use regular expressions." Now they have two problems.

I can't wait for you to get into LINQ and other data structures like lists. Those may make you want to refactor this :p.

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christian lian huat toh

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C# Challenge ( ADDRESS BOOK )

1 Answer

Jon Wood

Jon Wood

christian lian huat toh

christian lian huat toh